Part Number: UCC28780 Hello,
I am using UCC28780EVM-021. It was working properly but suddenly it is not working. I have not changed any components and the pins HVG, CS, Rtz and Rdm are not short or open circuited. I don't know the problem. I am attaching…
Part Number: UCC28780 Hello,
I am using UCC28780EVM-021. When I connect it to power supply and start increasing the voltage from 0VAC, I am observing 3 different kind of PWM pulses upto Brown-IN voltage i.e. apprx. 75VAC.
1. 0VAC to 45VAC
2. 45VAC…
Hi Harish,
I did the experiment you suggested and (of course...) the working board still works after replacing the controller...
So I started to desolder and measure every single resistor and capacitor connected to the controller on the broken board…
Part Number: UCC28780 Hello,
I have the 45Watt demoboard - UCC28780EVM-021, and I want understand how I can move down the start up undervoltage from 107 VDC to 95V DC or 90VDC. Can you please help me?
Wilhelm
Hello Ulrich,
Thank you for your quick answer. Ok next time I will follow the datasheet method ^^'
Unfortunately, I have done my layout based on the schematic of the eval board (UCC28780EVM-021).
The excel tool give a Rbias1 = 11 k and Rbias2 =…
Hi Ulrich,
Thanks for your reply.
I am looking 92% efficiency at 115Vrms and at Full load which is not average efficiency. I see 94.06% efficiency at 115Vrms and Full load in UCC28780EVM-021. I understand we have to select external component by carefully…
Part Number: UCC28780EVM-021 Other Parts Discussed in Thread: UCC28780
Above screenshot is the startup test waveform on Q2' Source and Gate in UCC28780EVM-02 . The ramp-up time is around 50ms.
We prototyped the circuit with Q2 replaced by BSP135 and…
Part Number: UCC28780EVM-021 Other Parts Discussed in Thread: UCC28780 , UCC28070 Hi Team,
We have got UCC28780EVM-021, 45-W, 20-V High-Density Silicon (Si) Based, Active-Clamp Flyback Converter/Evaluation Module. We tested the kit for line and load…
Hi Ulrich & Jaden
Replace the transformer on UCC28780EVM-021 EVK with Npsa=32:2:6 & Lp=110uH, connect the VDD of the UCC24612 on the secondary side to the 5V output, and R24 &R26=100K, but the 5V output voltage is unstable, could you help to check it…
Hi Takahiro-san,
Thanks for reaching out. Please share with your customer UCC28780 which is an active clamp flyback controller. TI has two EVM designs available: UCC28780EVM-002 which uses GaN and UCC28780EVM-021 which uses Si MOSFET.
Best Regards…
